In case you were curious about the amount of work involved in keeping out forum spam and how rampant it is, take this afternoon as a good example. For just 30 minutes I turned off our Stop Forum Spam plugin to allow someone to register who couldn't get through our spam filter. During that time we had the following occur: 25 fake accounts registered with IP addresses all over Europe and China who posted urls in various parts of their account and some tried to post. 1 fake account with an IP address from China that posted no less than 87 times within a span of about 10 minutes (we will change the post timeouts). 7 spam forum posts, some of which were stuck in the moderation queue. These types of abuses are rampant and there is virtually no ability to fight them, only prevent them. Outside the US there is very little policing. Within the US the best you can try to do is have the accounts responsible canceled, assuming that the accounts are owned by the spammer and not breached and that you have an ISP who is willing to take action.